Who We Serve Solutions News FAQ Contact → +49 89 24414745-0
3 manufacturers: CORNEX, CUBENERGY, Hoymiles
835 kWh–16 MWh per AC block, scaling to GWh projects
96.5% round-trip efficiency on CORNEX cells
12,000+ rated cycles on the 588 Ah cell
48 h until you hear back from us
Who We Serve

Who we work with

Most conversations start with one of these four teams. Each needs something different from us, so here is what that looks like in practice.

BESS project developers and system integrators

Developers & integrators

  • Factory pricing, with one intermediary in the chain: us
  • Anything from one 835 kWh block to multi-GWh pipelines
  • LFP systems your lenders already know (BloombergNEF Tier 1)
  • A first reply within 48 hours
EPC engineering and construction site for BESS projects

EPCs & contractors

  • Drawings, datasheets and IEC/UL certificates before you sign
  • AC-integrated or DC-only, depending on how much you integrate yourself
  • Someone in Munich chasing the factory when a date slips
  • Warranty and after-sales sorted with the manufacturer
High voltage electricity pylons for utilities and grid operators

Utilities & grid operators

  • Systems specified for FCR, aFRR and mFRR
  • Reference sites in Germany, Finland and Denmark
  • Black start and grid-forming capability where you need it
  • Long-term O&M through the manufacturer
Infrastructure investors and funds evaluating BESS assets

Investors & funds

  • Bankability files ready for technical due diligence
  • Cycle-life test data, not just brochure numbers
  • BloombergNEF Tier 1 manufacturers with DNV credentials
  • A straight answer when a spec looks too good to be true
OEM Partners

Three manufacturers, and how to choose between them

The short version: if you want a complete system that connects straight to the grid, look at CUBENERGY. If you want DC containers and a medium-voltage station from one supplier, look at Hoymiles. If your team integrates its own PCS, CORNEX gives you the most freedom. Not sure yet? That is what the first call is for.

CUBENERGY logo
CUBEENERGY
Complete AC system, PCS included

CUBENERGY builds complete AC systems: battery, PCS, BMS and grid interface in one unit, using CORNEX LFP cells. The PowerCombo-E5 puts 5 MWh in a 20 ft container. The FlexCombo 2.0 scales from 835 kWh to 16 MWh per block. CUBENERGY has installed 3,580 MWh across more than 220 projects in Europe.

  • PCS, BMS and grid interface included
  • PowerCombo-E5: 5 MWh in 20 ft · FlexCombo 2.0: up to 16 MWh
  • Same CORNEX LFP cells as the DC systems
  • UL9540, CE, DNV
Hoymiles logo
hoymiles
DC containers plus a medium-voltage station

Hoymiles pairs its HoyDC 5MWh DC container with the HIM5175MV station, which puts the PCS, transformer and switchgear on one skid. You get a direct 10–35 kV grid connection without sourcing the MV side separately. Rated for 8,000+ cycles, IP55, certified to UL9540A and IEC 62619.

  • HoyDC 5MWh · 1164.8–1500 V · ≥8,000 cycles to 70% SOH
  • HIM5175MV · 5,175 kVA · 10–35 kV AC grid connection
  • PCS, transformer and RMU on one skid, so installation is quicker
  • UL9540A, IEC 62619, IEC 62477-1 · liquid cooling
CORNEX New Energy logo
CORNEX
DC containers, bring your own PCS

CORNEX makes the cells inside both its own containers and CUBENERGY’s. The M5 (5 MWh) and M6 (6.25 MWh) DC containers suit EPCs who want to choose and integrate their own PCS. CORNEX was one of the five largest storage battery suppliers worldwide in 2025 and delivered more than 90 GWh that year.

  • DC only, so you choose the PCS
  • M5: 5 MWh · M6: 6.25 MWh, both in 20 ft
  • Up to 96.5% efficiency · 12,000+ cycles · 190 Wh/kg
  • FCR and aFRR ready · BloombergNEF Tier 1 · D&B 5AA1
Reference Projects

Where these systems are already running

These are our manufacturers’ projects, not ours. We think that is the more useful thing to show you: real sites and real sizes, in grids like yours.

220+ European projects · 2,475 MW / 3,580 MWh installed (CUBENERGY, Dec 2025) · 90+ GWh delivered globally (CORNEX, 2025)

Selected Projects

CUBENERGY in Europe

CUBENERGY 135MW/270MWh Leipzig Germany Standalone BESS
CUBENERGY
135 MW / 270 MWh
Standalone BESS · Leipzig, Germany

PowerCombo E5 AC Block · Frequency regulation, instantaneous reserve capacity & grid-forming inertia support · Energy arbitrage · Two sites: 90 MW/180 MWh + 45 MW/90 MWh

CUBENERGY 40MW/80MWh Finland Grid Ancillary Service
CUBENERGY
40 MW / 80 MWh
Grid Ancillary Service · Finland · 2024

PowerCombo-20C2H1200K · ms-level frequency response · FCR/FRR market · Renewable integration

CUBENERGY 30MW/43MWh Denmark TSO Black Start
CUBENERGY
30 MW / 43 MWh
Grid Auxiliary Service · Denmark · TSO

PowerCombo-20C2H1200K · Largest BESS in Denmark · Black Start capability · TSO flexibility services

CORNEX in Bulgaria and China

CORNEX containers shipped — RESTORE Bulgaria project
CORNEX
1,110 MWh
RESTORE Project · Bulgaria · Benchmark

Government benchmark project · Facilitates Bulgaria's energy transition · Grid stability & renewable integration · Wind + BESS

CORNEX 1000MW/4000MWh URUMQI China — aerial view
CORNEX
1,000 MW / 4,000 MWh
Standalone BESS · Urumqi, China · Huadian

World-scale standalone BESS · China Huadian · Grid stabilisation · Xinjiang renewable integration

Process

What working with us looks like

Four steps. The last one takes the longest, and it is where we are most useful.

1

You tell us what you need

Size in MW and MWh, location, use case and timing. Rough numbers are fine. You will hear back within 48 hours.

2

We suggest a system

We work out which of the three manufacturers fits and put together a technical and commercial offer. If none of them is right for your project, we will say so.

3

You get the paperwork

Certificates, cell test data and warranty terms, in the form your lenders and investors expect.

4

We stay on it until it runs

Between contract and go-live there is factory scheduling, shipping to Europe, site logistics and commissioning. We sit between you and the factory the whole way, in your time zone and your language.

Why mellon.energy

Why go through us at all?

Fair question. You could call the factories yourself. Here is what we add.

We know the people at the factory

We work directly with CORNEX, CUBENERGY and Hoymiles. When you need a firm answer on a delivery date or a spec, we know who to ask, and we usually get it faster than a cold email would.

25 years of doing business in China

Our team in Munich has spent more than 25 years working with Chinese companies. We know how decisions get made there, what gets lost in translation, and how to keep a project on track across two very different ways of working.

Documents before you need them

Certificates, bankability files and technical documentation, prepared up front rather than after your lender asks for them.

News

News from our manufacturers

CUBENERGY FlexCombo BESS
CUBENERGY · Product

CUBENERGY launches FlexCombo 2.0, up to 16 MWh per block

The new AC block platform covers utility and C&I projects, with cloud BMS and plug-and-play installation.

Read more →
CORNEX global market
CORNEX · Market

CORNEX is now a top-5 global supplier of storage batteries

Founded by Dai Deming in 2021, CORNEX reached the global top five for storage shipments in the first half of 2025. It ranks second for effective production capacity.

Read more →
CORNEX 588Ah LFP cell technology
CORNEX · Technology

CORNEX’s 588 Ah cell: 12,000 cycles at 96.5% efficiency

The large-format LFP cell reaches 190 Wh/kg and 419 Wh/L, which means more storage in the same container footprint.

Read more →
Lithium market

Lithium carbonate prices in China

Battery grade 99.5% Li₂CO₃  ·  CNY / tonne  ·  GFEX futures

Current 124,950 CNY/t
3M -16.1% vs. 3 months ago
52w High 200,500 CNY/t
52w Low 73,500 CNY/t
YTD -15.6% since Jan 1
Lithium carbonate rallied from about 60,000 to a two-year high of 200,500 CNY per tonne, then eased back to around 125,000 CNY per tonne.

Why we show this

Lithium carbonate is one of the biggest inputs into what a battery system costs. When it moves, quotes follow. We keep an eye on it so we can tell you whether now is a good moment to lock in a price.

Current price and recent trend per Trading Economics (two-year high of 200,500 CNY/t on May 13, 2026); earlier 2025 trend estimated from InfoLink Consulting / SMM data. Daily values interpolated between confirmed anchor points. For market context only — not investment advice.

Sources: Trading Economics  ·  InfoLink / SMM

FAQ

Questions we get a lot

We sit between European project teams and three Chinese BESS manufacturers: CORNEX, CUBENERGY and Hoymiles. We help you choose a system, get a quote and the documents your financing needs, and then coordinate with the factory through delivery and commissioning. We are based near Munich.
CORNEX New Energy is a battery manufacturer from Wuhan, founded in 2021 by Dai Deming. It makes cells, battery containers and complete storage systems, and has built more than 110 GWh of production capacity across several sites in Hubei province. In 2025 it was among the five largest suppliers of energy storage batteries in the world.
CUBENERGY is a BESS integrator founded in 2014. Its European headquarters is in Düsseldorf, with service and stock locations in Sweden and France, and R&D and manufacturing in China and the US. It builds standardised, containerised systems for C&I and utility-scale projects, and handles design, grid-code compliance, commissioning and service. By the end of 2025 it had installed 3,580 MWh across more than 220 projects in Europe.
Around 27.1 GWh of new battery storage was installed in Europe in 2025, 45% more than the year before. Some forecasts put total capacity at up to 750 GWh by 2030. Batteries are used for grid services such as FCR and aFRR, for peak shaving, for shifting consumption to cheaper hours and for storing solar and wind power. More and more projects pair batteries directly with a solar or wind park.
Anything from an 835 kWh C&I system to multi-GWh utility projects. That includes FCR, aFRR and mFRR, peak shaving, load shifting, solar or wind plus storage, grid congestion relief, island grids, backup power and capacity markets.
Call us on +49 89 24414745-0 or use the form below. Tell us where the project is, how many MW and MWh you need, what it is for and when. Rough numbers are fine to start with.

The people you will be talking to

When you get in touch, one of us answers. Not a sales queue.

Moritz Klinkisch, Geschäftsführer mellon.energy

Moritz Klinkisch

Managing Director

Sales & business development

LinkedIn
Laura Peschke, Geschäftsführerin mellon.energy

Laura Peschke

Managing Director

Marketing & PR

LinkedIn
Contact

Tell us about your project

Even if it is early and the numbers are rough. A first conversation costs nothing and does not commit you to anything.

Phone

+49 89 24414745-0

Confidential

We don’t share your project details without your OK.

Email

info@mellon.energy

Send us the basics

Size, location, use case, timing. We will reply within 48 hours.